diff options
| -rw-r--r-- | sys-utils/mount.8 | 335 |
1 files changed, 8 insertions, 327 deletions
diff --git a/sys-utils/mount.8 b/sys-utils/mount.8 index 15aa5f1db..c5f7c1408 100644 --- a/sys-utils/mount.8 +++ b/sys-utils/mount.8 @@ -1206,6 +1206,14 @@ only for root users. The option is also supported as x-mount.mkdir, this notati is deprecated for mount.mkdir since v2.30. .SH "FILESYSTEM-SPECIFIC MOUNT OPTIONS" +You should consult the respective man page for the filesystem first. +If you want to know what options the ext4 filesystem supports, then check the +.BR ext4 (5) +man page. +If that doesn't exist, you can also check the corresponding mount page like +.BR mount.cifs (8). +Note that you might have to install the respective userland tools. +.sp The following options apply only to certain filesystems. We sort them by filesystem. They all follow the .B \-o @@ -1277,200 +1285,6 @@ These options are accepted but ignored. (However, quota utilities may react to such strings in .IR /etc/fstab .) -.SS "Mount options for btrfs" -Btrfs is a copy-on-write filesystem for Linux aimed at -implementing advanced features while focusing on fault tolerance, -repair, and easy administration. -.TP -.BI alloc_start= bytes -Debugging option to force all block allocations above a certain -byte threshold on each block device. The value is specified in -bytes, optionally with a K, M, or G suffix, case insensitive. -Default is 1MB. -.TP -.B autodefrag -Disable/enable auto defragmentation. -Auto defragmentation detects small random writes into files and queues -them up for the defrag process. Works best for small files; -not well-suited for large database workloads. -.TP -.BR check_int | check_int_data | check_int_print_mask =\fIvalue\fR -These debugging options control the behavior of the integrity checking -module(the BTRFS_FS_CHECK_INTEGRITY config option required). - -.B check_int -enables the integrity checker module, which examines all -block-write requests to ensure on-disk consistency, at a large -memory and CPU cost. - -.B check_int_data -includes extent data in the integrity checks, and -implies the check_int option. - -.B check_int_print_mask -takes a bitmask of BTRFSIC_PRINT_MASK_* values -as defined in fs/btrfs/check-integrity.c, to control the integrity -checker module behavior. - -See comments at the top of -.IR fs/btrfs/check-integrity.c -for more info. -.TP -.BI commit= seconds -Set the interval of periodic commit, 30 seconds by default. Higher -values defer data being synced to permanent storage, with obvious -consequences when the system crashes. The upper bound is not forced, -but a warning is printed if it's more than 300 seconds (5 minutes). -.TP -.BR compress | compress= \fItype\fR| compress-force | compress-force= \fItype\fR -Control BTRFS file data compression. Type may be specified as "zlib" -"lzo" or "no" (for no compression, used for remounting). If no type -is specified, zlib is used. If \fBcompress-force\fR is specified, -all files will be compressed, whether or not they compress well. -If compression is enabled, \fBnodatacow\fR and \fBnodatasum\fR are disabled. -.TP -.B degraded -Allow mounts to continue with missing devices. A read-write mount may -fail with too many devices missing, for example if a stripe member -is completely missing. -.TP -.BI device= devicepath -Specify a device during mount so that ioctls on the control device -can be avoided. Especially useful when trying to mount a multi-device -setup as root. May be specified multiple times for multiple devices. -.TP -.B discard -Disable/enable the discard mount option. -The discard function issues frequent commands to let the block device -reclaim space freed by the filesystem. -This is useful for SSD devices, thinly provisioned -LUNs and virtual machine images, but may have a significant -performance impact. (The \fBfstrim\fR command is also available to -initiate batch trims from userspace.) -.TP -.B enospc_debug -Disable/enable debugging option to be more verbose in some ENOSPC conditions. -.TP -.BI fatal_errors= action -Action to take when encountering a fatal error: - "bug" - BUG() on a fatal error. This is the default. - "panic" - panic() on a fatal error. -.TP -.B flushoncommit -The -.B flushoncommit -mount option forces any data dirtied by a write in a -prior transaction to commit as part of the current commit. This makes -the committed state a fully consistent view of the filesystem from the -application's perspective (i.e., it includes all completed filesystem -operations). This was previously the behavior only when a snapshot is -created. -.TP -.B inode_cache -Enable free inode number caching. Defaults to off due to an overflow -problem when the free space CRCs don't fit inside a single page. -.TP -.BI max_inline= bytes -Specify the maximum amount of space, in bytes, that can be inlined in -a metadata B-tree leaf. The value is specified in bytes, optionally -with a K, M, or G suffix, case insensitive. In practice, this value -is limited by the root sector size, with some space unavailable due -to leaf headers. For a 4k sectorsize, max inline data is ~3900 bytes. -.TP -.BI metadata_ratio= value -Specify that 1 metadata chunk should be allocated after every -.I value -data chunks. Off by default. -.TP -.B noacl -Enable/disable support for Posix Access Control Lists (ACLs). See the -.BR acl (5) -manual page for more information about ACLs. -.TP -.B nobarrier -Enable/disable the use of block-layer write barriers. Write barriers -ensure that certain IOs make it through the device cache and are on -persistent storage. If disabled on a device with a volatile -(non-battery-backed) write-back cache, the \fBnobarrier\fR option will -lead to filesystem corruption on a system crash or power loss. -.TP -.B nodatacow -Enable/disable data copy-on-write for newly created files. -This option implies \fBnodatasum\fR, and disables all compression. -.TP -.B nodatasum -Enable/disable data checksumming for newly created files. -This option implies \fBdatacow\fR. -.TP -.B notreelog -Enable/disable the tree logging used for fsync and O_SYNC writes. -.TP -.B recovery -Enable autorecovery attempts if a bad tree root is found at mount time. -Currently this scans a list of several previous tree roots and tries to -use the first readable. -.TP -.B rescan_uuid_tree -Force check and rebuild procedure of the UUID tree. This should not -normally be needed. -.TP -.B skip_balance -Skip automatic resume of an interrupted balance operation after mount. -May be resumed with "btrfs balance resume." -.TP -.B nospace_cache -Disable freespace cache loading without clearing the cache. -.TP -.B clear_cache -Force clearing and rebuilding of the disk space cache if something -has gone wrong. -.TP -.BR ssd | nossd | ssd_spread -Options to control ssd allocation schemes. By default, BTRFS will -enable or disable ssd allocation heuristics depending on whether a -rotational or non-rotational disk is in use. The \fBssd\fR and -\fBnossd\fR options can override this autodetection. - -The \fBssd_spread\fR mount option attempts to allocate into big chunks -of unused space, and may perform better on low-end ssds. \fBssd_spread\fR -implies \fBssd\fR, enabling all other ssd heuristics as well. -.TP -.BI subvol= path -Mount subvolume at -.IR path -rather than the root subvolume. The -.IR path -is relative to the top level subvolume. -.TP -.BI subvolid= ID -Mount subvolume specified by an ID number rather than the root subvolume. -This allows mounting of subvolumes which are not in the root of the mounted -filesystem. -You can use "btrfs subvolume list" to see subvolume ID numbers. -.TP -.BI subvolrootid= objectid " \fR(deprecated)" -Mount subvolume specified by -.IR objectid -rather than the root subvolume. -This allows mounting of subvolumes which are not in the root of the mounted -filesystem. -You can use "btrfs subvolume show " to see the object ID for a subvolume. -.TP -.BI thread_pool= number -The number of worker threads to allocate. The default number is equal -to the number of CPUs + 2, or 8, whichever is smaller. -.TP -.B user_subvol_rm_allowed -Allow subvolumes to be deleted by a non-root user. Use with caution. - -.SS "Mount options for cifs" -See the options section of the -.BR mount.cifs (8) -man page (cifs-utils package must be installed). - -.SS "Mount options for coherent" -None. - .SS "Mount options for debugfs" The debugfs filesystem is a pseudo filesystem, traditionally mounted on .IR /sys/kernel/debug . @@ -1565,9 +1379,6 @@ starting with 2.6.29. Further, this option is valid only if CONFIG_DEVPTS_MULTIPLE_INSTANCES is enabled in the kernel configuration. -.SS "Mount options for ext2, ext3 and ext4" -See the options section of the ext2(5), ext3(5) or ext4(5) man page (the e2fsprogs package must be installed). - .SS "Mount options for fat" (Note: .I fat @@ -1961,9 +1772,6 @@ or remount the filesystem read-only, or panic and halt the system.) .BR noquota | quota | usrquota | grpquota These options are accepted but ignored. -.SS "Mount options for minix" -None. - .SS "Mount options for msdos" See mount options for fat. If the @@ -1983,21 +1791,6 @@ and the current version of .B mount (2.12) does not know anything about ncpfs. -.SS "Mount options for nfs and nfs4" -See the options section of the -.BR nfs (5) -man page (the nfs-utils package must be installed). - -The -.IR nfs " and " nfs4 -implementation expects a binary argument (a -.IR "struct nfs_mount_data" ) -to the mount system call. This argument is constructed by -.BR mount.nfs (8) -and the current version of -.B mount -(2.13) does not know anything about nfs and nfs4. - .SS "Mount options for ntfs" .TP .BI iocharset= name @@ -2067,16 +1860,6 @@ The upperdir is normally on a writable filesystem. .BI workdir= directory The workdir needs to be an empty directory on the same filesystem as upperdir. -.SS "Mount options for proc" -See the options section of the -.BR proc (5) -man page. - -.SS "Mount options for ramfs" -Ramfs is a memory based filesystem. Mount it and you have it. Unmount it -and it is gone. -There are no mount options. - .SS "Mount options for reiserfs" Reiserfs is a journaling filesystem. .TP @@ -2178,100 +1961,6 @@ proper on-disk ordering of journal commits, making volatile disk write caches safe to use, at some performance penalty. If your disks are battery-backed in one way or another, disabling barriers may safely improve performance. -.SS "Mount options for romfs" -None. - -.SS "Mount options for squashfs" -None. - -.SS "Mount options for smbfs" -Just like -.IR nfs ", the " smbfs -implementation expects a binary argument (a -.IR "struct smb_mount_data" ) -to the mount system call. This argument is constructed by -.BR smbmount (8) -and the current version of -.B mount -(2.12) does not know anything about smbfs. - -.SS "Mount options for sysv" -None. - -.SS "Mount options for tmpfs" -.TP -.BI size= nbytes -Override default maximum size of the filesystem. -The size is given in bytes, and rounded up to entire pages. -The default is half of the memory. The size parameter also accepts a suffix % -to limit this tmpfs instance to that percentage of your physical RAM: -the default, when neither size nor nr_blocks is specified, is size=50% -.TP -.B nr_blocks= -The same as size, but in blocks of PAGE_CACHE_SIZE -.TP -.B nr_inodes= -The maximum number of inodes for this instance. The default -is half of the number of your physical RAM pages, or (on a -machine with highmem) the number of lowmem RAM pages, -whichever is the lower. -.PP -The tmpfs mount options for sizing (\c -.BR size , -.BR nr_blocks , -and -.BR nr_inodes ) -accept a suffix -.BR k , -.B m -or -.B g -for Ki, Mi, Gi (binary kilo (kibi), binary mega (mebi) and binary giga (gibi)) and can be changed on remount. - -.TP -.B mode= -Set initial permissions of the root directory. -.TP -.B uid= -The user id. -.TP -.B gid= -The group id. -.TP -.B mpol=[default|prefer:Node|bind:NodeList|interleave|interleave:NodeList] -Set the NUMA memory allocation policy for all files in that -instance (if the kernel CONFIG_NUMA is enabled) \(en which can be adjusted on the -fly via 'mount \-o remount \&...' -.RS -.TP -.B default -prefers to allocate memory from the local node -.TP -.B prefer:Node -prefers to allocate memory from the given Node -.TP -.B bind:NodeList -allocates memory only from nodes in NodeList -.TP -.B interleave -prefers to allocate from each node in turn -.TP -.B interleave:NodeList -allocates from each node of NodeList in turn. -.PP -The NodeList format is a comma-separated list of decimal numbers and ranges, a -range being two "hyphen-minus"-separated decimal numbers, the smallest and largest node -numbers in the range. For example, mpol=bind:0\(en3,5,7,9\(en15 - -Note that trying to mount a tmpfs with an mpol option will fail if the -running kernel does not support NUMA; and will fail if its nodelist -specifies a node which is not online. If your system relies on that -tmpfs being mounted, but from time to time runs a kernel built without -NUMA capability (perhaps a safe recovery kernel), or with fewer nodes -online, then it is advisable to omit the mpol option from automatic -mount options. It can be added later, when the tmpfs is already mounted -on MountPoint, by 'mount \-o remount,mpol=Policy:NodeList MountPoint'. - .SS "Mount options for ubifs" UBIFS is a flash filesystem which works on top of UBI volumes. Note that \fBatime\fR is not supported and is always turned off. @@ -2527,14 +2216,6 @@ Set the owner and group and mode of the file .I devices (default: uid=gid=0, mode=0444). The mode is given in octal. -.SS "Mount options for xenix" -None. - -.SS "Mount options for xfs" -See the options section of the -.BR xfs (5) -man page (the xfsprogs package must be installed). - .SH "THE LOOP DEVICE" One further possible type is a mount via the loop device. For example, the command |